Betamimetics (β-adrenergic substances) are discussed in U.S. Pat. No. 4,460,581, which proposes betamimetics for the treatment of a range of diseases.
For drug treatment of diseases it is often desirable to prepare medicaments with a longer duration of activity. As a rule, this ensures that the concentration of the active substance in the body needed to achieve the therapeutic effect is guaranteed for a longer period without the need to re-administer the drug at frequent intervals. Moreover, giving an active substance at longer time intervals contributes to the well-being of the patient to a high degree.
It is particularly desirable to prepare a pharmaceutical composition which can be used therapeutically by administration once a day (single dose). The use of a drug once a day has the advantage that the patient can become accustomed relatively quickly to regularly taking the drug at certain times of the day.
The aim of the present invention is therefore to provide betamimetics which on the one hand confer a therapeutic benefit in the treatment of respiratory complaints and are also characterized by a longer duration of activity and can thus be used to prepare pharmaceutical compositions with a longer duration of activity. A further objective of the present invention is to prepare betamimetics which, by virtue of their long-lasting effect, can be used to prepare a drug for administration once a day for treating respiratory complaints. Another objective of the invention, apart from those mentioned above, is to prepare betamimetics which are not only exceptionally potent but are also characterized by a high degree of selectivity with respect to the β2-adrenoceptor. In addition, the invention sets out to prepare betamimetics which because of their physicochemical properties can be used in particular for preparing pharmaceutical formulations which are particularly suitable for administration by inhalation. The invention also relates to the preparation of betamimetics, which in addition to having the above-mentioned properties, are also particularly suitable for preparing inhalable powders and suspension aerosols.